0650: Ralf Schumacher's engine has failed and he will start on the back of the grid.

0640: Coulthard, Barrichello, Trulli, Villeneuve, Heidfeld and Massa are eliminated after the second qualifying session.

0615: Speed, Liuzzi, Albers, Monteiro, Sato and Ide are eliminated after the first qualifying session.

0600: Four drivers are facing 10-place grid penalities for unscheduled engine changes - David Coulthard, Michael Schumacher, Felipe Massa and Rubens Barrichello. None can now start higher than 11th on the grid for Sunday's race.

All 22 cars run for the first 15 minutes, at the end of which the slowest six will be eliminated and fill the final six places on the grid in order of their lap times.

The same elimination process will happen at the end of the second 15 minutes, with the next six slowest cars knocked out to fill places 11 to 16 on the grid in lap-time order.

Finally, the fastest 10 cars will shoot it out for the top 10 places for the final 20 minutes - but with the amount of fuel with which they will start the race, with fuel being put back into the car after qualifying according to a pre-arranged formula.

Last weekend, at the first race of the season in Bahrain, the system caught out two leading runners.

McLaren's Kimi Raikkonen suffered a suspension failure in the first session and was eliminated, leaving him at the back of the grid.

And seven-time champion Michael Schumacher fell foul of a rule that ensures drivers in the final session must complete every lap within 110% of pole position.

For any lap outside that time, a driver is docked one lap's worth of fuel for the race, which harms his strategy.